(1B) The product $(a+b)(c+d)$
Practice
Expand and simplify.
*Write your answers with powers of $x$ in descending order. $\left(\square x^2 \pm \square x \pm \square\right)$
$\left(x+6\right)\left(x-9\right)$
$\left(x-8\right)\left(x+9\right)$
$\left(-x+4\right)\left(4+x\right)$
$\left(-x+1\right)\left(2-x\right)$
$\left(1-x\right)\left(-x+1\right)$
$\left(7-x\right)\left(x+3\right)$
$\left(3-x\right)\left(3-x\right)$
$\left(-9+x\right)\left(-6+x\right)$
$\left(-x+1\right)\left(x+3\right)$
$\left(x-3\right)\left(-6x+1\right)$
$\left(2x+1\right)\left(2-9x\right)$
$\left(x+8\right)\left(2-9x\right)$
$\left(6-x\right)\left(-8x+3\right)$
$\left(5-3x\right)\left(2x-3\right)$
$\left(-3+5x\right)\left(-3+x\right)$
$\left(1-x\right)\left(8+7x\right)$